CA1106666A - Fiber optic connector for single fiber - Google Patents
Fiber optic connector for single fiberInfo
- Publication number
- CA1106666A CA1106666A CA294,055A CA294055A CA1106666A CA 1106666 A CA1106666 A CA 1106666A CA 294055 A CA294055 A CA 294055A CA 1106666 A CA1106666 A CA 1106666A
- Authority
- CA
- Canada
- Prior art keywords
- connector
- pin
- fiber
- aperture
- connector pin
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/36—Mechanical coupling means
- G02B6/38—Mechanical coupling means having fibre to fibre mating means
- G02B6/3807—Dismountable connectors, i.e. comprising plugs
- G02B6/3833—Details of mounting fibres in ferrules; Assembly methods; Manufacture
- G02B6/3855—Details of mounting fibres in ferrules; Assembly methods; Manufacture characterised by the method of anchoring or fixing the fibre within the ferrule
- G02B6/3861—Adhesive bonding
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/36—Mechanical coupling means
- G02B6/38—Mechanical coupling means having fibre to fibre mating means
- G02B6/3807—Dismountable connectors, i.e. comprising plugs
- G02B6/3833—Details of mounting fibres in ferrules; Assembly methods; Manufacture
- G02B6/3847—Details of mounting fibres in ferrules; Assembly methods; Manufacture with means preventing fibre end damage, e.g. recessed fibre surfaces
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/36—Mechanical coupling means
- G02B6/38—Mechanical coupling means having fibre to fibre mating means
- G02B6/3807—Dismountable connectors, i.e. comprising plugs
- G02B6/3873—Connectors using guide surfaces for aligning ferrule ends, e.g. tubes, sleeves, V-grooves, rods, pins, balls
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/36—Mechanical coupling means
- G02B6/38—Mechanical coupling means having fibre to fibre mating means
- G02B6/3807—Dismountable connectors, i.e. comprising plugs
- G02B6/3873—Connectors using guide surfaces for aligning ferrule ends, e.g. tubes, sleeves, V-grooves, rods, pins, balls
- G02B6/3874—Connectors using guide surfaces for aligning ferrule ends, e.g. tubes, sleeves, V-grooves, rods, pins, balls using tubes, sleeves to align ferrules
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/36—Mechanical coupling means
- G02B6/38—Mechanical coupling means having fibre to fibre mating means
- G02B6/3807—Dismountable connectors, i.e. comprising plugs
- G02B6/3887—Anchoring optical cables to connector housings, e.g. strain relief features
- G02B6/3889—Anchoring optical cables to connector housings, e.g. strain relief features using encapsulation for protection, e.g. adhesive, molding or casting resin
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/36—Mechanical coupling means
- G02B6/38—Mechanical coupling means having fibre to fibre mating means
- G02B6/3807—Dismountable connectors, i.e. comprising plugs
- G02B6/3833—Details of mounting fibres in ferrules; Assembly methods; Manufacture
- G02B6/3854—Ferrules characterised by materials
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Mechanical Coupling Of Light Guides (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A connector and coupling assembly to couple a single pair of optical fibers provides for securing the respective fibers in identical metallic connector pins and inserting these pins in an alignment sleeve having a precision axial aperture which maintains proper alignment of the pins and the fibers carried thereby. The respective connector pins are carried by coupling members which resiliently hold the pins so as to allow alignment thereof by the alignment sleeve while the coupling members provide for axial clamping of the pins together in axial alignment.
A connector and coupling assembly to couple a single pair of optical fibers provides for securing the respective fibers in identical metallic connector pins and inserting these pins in an alignment sleeve having a precision axial aperture which maintains proper alignment of the pins and the fibers carried thereby. The respective connector pins are carried by coupling members which resiliently hold the pins so as to allow alignment thereof by the alignment sleeve while the coupling members provide for axial clamping of the pins together in axial alignment.
Description
BACKGROUND OF THE INVENTION
. , -' , The present invention relates in general to connectors and couplers ~or optical fibers, and more specifically, to connectors and couplers of extremely simple construction which are eFfective to accurately align and couple individual pairs of optical fibers.
Recently~ significant research and development has been extended into the ~jeld ~f optical-communication systems, inciuding, but not limited to telephony, data processing, television, and various control appl;cations.
The great interest in the use of optical fibers for various communication applications results from the very high available band width, immunity ~rom electro-magnetic interference, communication security~ small size, lo~ -weight and lack of need for strategic materials. However~ the need to eff~ciently couple such optical fibers, which can be a serious problem due to the extremely small dimensions thereof, provides a serious limitation on the use of such communication waveguides. Thus, connectors and couplers for optical fibers are an important aspect of an effective optical communication system in that they have a direct bearing on the degree a-F optical losses and the relative ease of installation and maintenance of the system in the ~ield.
Connectors and couplers for optical fibe~s fa71 generally into two classes. In a ~irst class, a single coupler îs used to interconnect an entiré bundle of optical -Fiber strands. A second c~ass provides a separate coupler to interconnect each sîngle pair of fiber strands. With respect at ~-least to optical ~communications over substantial distances~ the trend has been to employ the single fioer and sin91e ~iber connector concepts, pri~arily because of economic and loss considerations.
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. , -' , The present invention relates in general to connectors and couplers ~or optical fibers, and more specifically, to connectors and couplers of extremely simple construction which are eFfective to accurately align and couple individual pairs of optical fibers.
Recently~ significant research and development has been extended into the ~jeld ~f optical-communication systems, inciuding, but not limited to telephony, data processing, television, and various control appl;cations.
The great interest in the use of optical fibers for various communication applications results from the very high available band width, immunity ~rom electro-magnetic interference, communication security~ small size, lo~ -weight and lack of need for strategic materials. However~ the need to eff~ciently couple such optical fibers, which can be a serious problem due to the extremely small dimensions thereof, provides a serious limitation on the use of such communication waveguides. Thus, connectors and couplers for optical fibers are an important aspect of an effective optical communication system in that they have a direct bearing on the degree a-F optical losses and the relative ease of installation and maintenance of the system in the ~ield.
Connectors and couplers for optical fibe~s fa71 generally into two classes. In a ~irst class, a single coupler îs used to interconnect an entiré bundle of optical -Fiber strands. A second c~ass provides a separate coupler to interconnect each sîngle pair of fiber strands. With respect at ~-least to optical ~communications over substantial distances~ the trend has been to employ the single fioer and sin91e ~iber connector concepts, pri~arily because of economic and loss considerations.
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~ n addi,tion, the single optical fiber strand-to-strand connectors and couplers, of the prior art have been of generally large size so that use QF such couplers in a multi-strand cable of large size may be difficult, i~ nQt impossible. One such pr;or art connector and coupler arrangement i$ disclosed in U. $. Patent No. 3,914,880, issued to Dakss et al on October 28~ 1~75~ In th.e patented arrangement, the end of each optical fiber to be joi,ned is~ attached within a glass capillary and each glass .' capilla,,ry i,s inserted into a hollow hard ~etal plug ~hose ou~er surface is groun~ t,o a preci,sion diameter. The t~lo metal plugs are then placed in ,face.-to-face relatiQnsh.ip in a precision ground Y grooYe formed in a rigid b,lQck and are he.ld in pl'ace by respectiYe clamping arrangements in which ' holding scre~s conta,ct the respect;ve metal plu~s and hold them forcéfully th;n the grq~ye so as to maintain alignment between the.connectors by yirtue of th.e. precision Y grooye and the prec;sion ground, diameter of the-respec~iye me.~al plugs.
The s,tructural arran~ement of the connector and coupler combination disclQsed in the aboye-referenced Dakss et al patent clearly is of undesir~
ab'ly l~rge s,ize and o~ complicated construction rendering it generally un-des;rable for use in coupling optical fiber strands in a ~ultistrand cable.
In a~iti,on, the pro,per ali,gnmen~ between the respective connectors depends i,n t~.e p~tented coupl.~r arrargement solely upon the e~fectiveness o~ ~he cIa,mping ~rra;ngement associa~ed ~ith ~he suppor~ block in which is provided th.e. precision ~round V groove, the respect;ue connectors being held in po$ition on the Y groove by separate clamp;ng arrangements. Thus, a loosen-in~ o~ either clamping arran~emen~ dur;n~ use ~or any reason' can result in a Inisalign ent or uncoupIing of ~he Fibers~
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SUMMARY OF THE INVENTION
An object of the invention is to provide an improved fiber-to-fiber ; connector and coupler arrangement that can be mated and unmated under normal uses withou-t mechanical failure.
A further object o-F the present invent;on is to provide a connector and ' coupler arrangement of the type described in which coupl;ng and alignment of a pair of optical fibers can be ~aintained consistently w;th an insertion loss of less than ab'out 1.5 db without the need for matching or coupling oil.
¦ An addltional object of ~he inven~ion is to provide an improved sinyle fiber connector and coupling arrangement that is economical to fabricate, easy to assemble, and has the inherent ability to provide for easy change of the ~
ends o~ the fibers to maintain minimum loss in communication transmission. -,' ' Further, an object of the invention is to provide an improved single fiber connector that is compatible for use with fibers which are either - polished or cùt.
'A still additional object oF the invention is to proYide a single fiber ¦ 'connector in ~hich the fiber ends are in -Firm but resilient contact so that i low coup7iny losses are present without suhjecting the fiber ends to undue stress.
- In accordance with the present invention, an assem~ly for connectin~
the stripped ends of a pair of single optical fibers ;ncludes a pair df connector halves each comprisin9 a connector pin made o~ a rigid materiàl having a circular cross section and being formed with an ax;ally concentric precision circular aperture extending throughout the length of the pin, the aperture being shaped and sized so as to permit the s~ripped end of one of the !single optical fibérs' to be snu91y positioned and bonded within the aperture so that the fiber end and one pjn end are substantially coextensi~e. In order ¦to couple the respective ends of the pair Df optical fibers, the respective connector pins are placed in juxtaposed position with the ends thereof in con~act and a rigid adapter tube or alignment sleeve is disposed around the pair of connector pins so as to enclose the junct;on thereof and the port;ons thereof on either side, the aperture o~ the rigid tube be;ng shaped and sized ¦so as to hold the connector p;ns in close axial alignment.
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01 Acco~ding to the present inven-tion, a rigid shell 02 encloses a portion of each connector pin and extends beyond the 03 other end of the connector pin. A quantity of flexible adhesive 04 material is disposed in at least a portion of the region between 05 the connector pin and the rigid shell for permitting slight 06 movement of the pin with respect to the shell. Coupling means is 07 secured to -the rigid shell of both connector halves Eor drawing 08 the connector pins into pressure contact, the flexible adhesive 09 material providing a spring bias so that a resilient support of the connector pins in intimate contact with one another is 11 maintained. The adhesive material advantageously has an elastic 12 limit which releases the bond between the shell and connector pin 13 when excessive forces are generated, thereby minimizing damage to 14 the assembly. A flexible tube having a high tensile strength and low modulus of elasticity is tightly disposed over the back end 16 of the rigid shell and around the unstripped fiber portion.
17 More generally, the invention is a connector for a ~18 single strand optical fiber comprising a generally cylindrical ~19 connector pin made of a rigid material and being forrned with an axially concentric precision circular aperture extending 21 throughout the length of the pin, the aperture being shaped and 22 sized to permit a stripped end of a single optical fiber to ke 23 snuggly positioned within the aperture and bonded therein, and so ~24 positioned that the fiber end and one end of the pin are coplanar. A shell made of a rigid material encloses a portion of ~26 the connector pin and has a back end extending beyond the other ;27 end of the connector pin. A quantit~ of a flexible adhesive 28 material is disposed in at least a portion of the region between 29 the connector pin and the shell for permitting a slight movement of the connector pin with respect to the shell. The shell is 31 connected via further structure to an unstripped fiber portion.
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01 More particularly, the invention is a coupling asse~nbly 02 for connecting the stripped ends of a pair of single optical 03 fibers, comprising a pair of connectors, an alignment sleeve and 04 coupling structure for the connector pins. The pair of 05 connec-tors each is comprised of a generally cylindrical connector 06 pin made of a metallic material and formed with an axially 07 concen-tric precision circular aperture extending throughout the 08 length of the pin, the aperture being shaped and sized to permit 09 the stripped end of one of the single optical fibers to be snuggly positioned wi-thin the aperture, the fiber being 50 11 positioned that the fib~r end and one pin end are substantially 12 coextensive, an adhesive structure disposed between the material 13 of the connector pin defining the aperture and the surface of the 14 single fiber positioned in the aperture for securing the fiber to the connector pin, a first flexible tube surrounding an ~16 unstripped fiber portion of the single fiber and having one end ~17 spaced from the other end of the connector pin, and a heat 18 deformable tube disposed around a portion of the connector pin.
19 The unstripped ~iber portion is adjacent the connector pin and ~20 the flexible tube and is in a heat deformed condition so as to 21 form a flexible junction of the Elexible tube and the connector 22 pin with the fiher disposed therein. A metallic shell encloses a 23 portion of the connector pin and has a back end extending beyond 24 the other end o~ the connector pin. A second flexible tube having high tensile strength is tightly disposed over the back 26 end of the metallic shell and extends along the heat deformed 27 tube beyond the connector. A quantity of a flexible adhesive 28 material is disposed in the region between the connector pin and 29 the metallic shell for permitting slight movement of the pin with respect to the shell. The pair o~ connectors are joined such 31 - 5a -6~
01 that the ends of the connector pins and the single fibers a'out to 02 form a junction of the pair of single fibers. The alignment 03 sleeve is made of a rigid material disposed around -the pair of 04 connector pins such as to enclose the junction thereof and -the 05 portions thereof on either side. The aperture of the alignment 06 sleeve is shaped and sized so as to hold the connector pins in 07 close axial alignmen-t. The coupling structure is secured to the 08 metallic shell of both connectors for drawing -the connector pins 09 into pressure contact, the ~lexible adhesive material in each connector providing a spring bias so that a biased junction of 11 the pair of optical fibers results.
12 The invention, more particularly, is a single fiber 13 connector assembly comprising a single fiber whose end is 14 stripped of a protective jacket, a protective pin made of a metallic material and being formed with an axially aligned 16 circular aperture extending throughout the length thereof, the 17 stripped end of the single fiber being positioned in the aperture 18 such that ends of the fiber and the pin lie on a common plane, 19 the diameter of the aperture being slightly greater than the diameter of the fiber, and a quantity of first adhesive material 21 disposed between the inner walls of the connector pin and the 22 fiber to hold the fiber secure with respect to the pin. A Teflon 23 tube surrounds the remaining portion of the stripped fiber for 24 protection of the fiber. A structure is provided for attaching the tube to the end of the connector pin. The assembly also 26 includes a connector body having an axially aligned aper-ture, the 27 connector pin and attached fiber being located in spaced 28 relationship within the aperture. Structure including a 29 resilient adhesive material is disposed in the space between the pin and the connector body for holding the pin within the 31 connector body. A metallic alignment tube has an axial aperture 32 - 5b -s~
01 of uniform central circular diameter slightly larger than the 02 outer diameter of the connector pin. The end of the pin is 03 positioned within the alignment tube such that one end thereof is 04 flush with the end of the connector body. The tube has a length 05 such that the connector pin end does not protrude through the end 06 thereof and thereby is adapted to receive a similar pin of 07 another connector assembly to be adjoined thereto.
0~ These and other objects, features, and advantages of 09 the presen-t invention will become more apparent from the following detailed description, when taken in conjunction wit~ ~-11 the accompanying drawings.
~12 BRIEF DESCRIPTION OF THE DRAWIMGS
13 Figure 1 is a longitudinal sectional view of the fiber ~14 optical connector in accordance with the present invention;
Figure 2 is a schematic view partly in section of the ~16 general coupling arrangement by which alignment of a pair oS
17 connector pins is effected in accordance with the present 18 invention;
19 Figure 3 is a longitudinal sectional view of an assembled optical fiber connector and coupling arrangement, 21 showing the positions of both male and female connector portions, 22 according to the present invention, 23 Figure 4 is a longitudinal sectional view of the 24 complete female connector portion, shown partially in Figure 3;
;25 and ~26 Figure 5 is a partial sectional view of the male 27 connector portion which is utilized in connection with the female 28 connector portion illustrated in Figure 4.
31 - 5c -DETAILE~ DESCRIPTION OF THE REFERRED EMBODLMENT5 In referr;ng to the seYeral figures of the drawing, like reference numerals are used to refer to identical parts of the articles described.
The bas;c connector element in accordance with the present invention is illustra-ted in Figure 1 in the form of a connector pin 12 of generally cylindrical conFiguration made of r7g;d material7 such as stainless steel, and being formed with an axially concentric prec;sion circular aperture extending throu~hout the length of the pin. The aperture in one end of the pin is formed with an enlarged opening extending a short distance from the end. A -'s;ngle fiber optic strand 10 having a portion of its protective jacke-t str;ppedis then inserted into the enlarged aperture of the connector pin so that the ~-junction of the stripped and unstr;pped portion oF the fiber is pressed against'-the seat formed by the transit;on between the large and small d;ameter portions,of the connector pin aperture. In this regard, the fiber 10 is str;pped of its protective jacket along the len9th of the strand for a distQnce which will Ipermit the bare fiber 11 to extend through the entire length of the aperture ~ -in the connector pin 12 and protrude slightly from the opposite end 1~' thereo-FSuitable adhesive is disposed between the material oF the connector pin 1~ ¦ -defining the aperture and the surface of the single fiber positioned in the aperture for securing the fiber to the connector pin- The end 12' of the -¦
connector pin from which the fiber protrudes is then precision ground thereby providing a planar surface including both the end of the connector pin and t:he ¦
end of the optical ~iber mounted therein.
In another method o~ alignin9 the end of the fiber with the end of the connector pin, a~portion of the protective jacket is stripped and the fiber is cleaned. The cut end of the fiber is aligned with the end a~ the connector Pin~ and the junction of the str;pped and unstripped fiber is merely located within the larger diameter opening of the connector pin, as opposed to l~eing press against the seat . ' ., ' I
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The type of adhesive used to bond the ~iber to the connector pin ' ' depends upon the type of fiber being used. ~here the single fiber is formed 1.
of a glass central core material and a glass cladding material, the adhesive should have an index of refrac-tion greater than that of the material of tie cladding so that optical power in the cladding dissipates as it passes through the connector. One suitable adhesive for this purpose is epoxy. Where the single fiber is formed of a glass central core material and a plastic cladding-¦material, the adhesive material should have an ~ndex o~ refraction less than that of the glass core material. A preferred'adhesive for this purpose is.a l':
silicon-base~ RTV adhesive material. . ' - .
Proper alignment between a pair of connector pins in accordance ~ith the present invention is accomplished by use of an alignment sleeve 15 which is s;zed so as to hold a pair of connector pins in close axial alignment, as illustrated in Fi~ure 2. In this regard, a connector pin 12a into which an optical fiber 10a has been mounted in the manner described in connection with .
Figure 1 and having a protective jacke~ 13a is inserted into one end of the ~.
ali4nment sleeve 15; wh;le, a:second connector pin 12b having an aptical ~ er ,10b mounted therein and including a protec.tive jacket 13b is inserted into 'I-opposite end of the alignment sleeve 15. Proper dimensioning of the aperture in the alignment sleeve 15 provides a simple means for effectin~ axial align- !ment between the respective connector plns, and there~ore,'proper alignment between the optical ~ibers mounted in the connector p;ns. ¦ -A coupling arrangement for the optical ~iber connectors in accordance- ¦ ' with the present invention is.illustrated in Fi~ure 3. As seen in the ~igure~
a first coupling member.20 having a threaded sleeve portion 21 is mounted on one end o~ a first connector pin 12a with the free end of the connector pin extending into one end of an alignment sleeve 15 carried therèby. A second coupling member 22 havin~ a threaded sleeve portion 23 is mounted on one end of a second connecting pin 12b so that the free end of the connecting pin extends into the other end of the alignment sleeve 15 in abutting relationship ith the connecting pin 12a. The connecting pins 12a and 12b are ~ormed in the manner described in connection with Figure I and alignment between these '. " : .
connecting pins is effected by means of the.al1gnrnent sleeve 15 as described in connection with Figure 2. - ~, Associated with the coupling member 20 is a third coupling member in the form of a nut 2~ having an internally threaded portion w~ich engages the threaded sleeve member 21 of the coupling member 20 and has an externally threaded sleeve portion 26 extending over the alignment sleeve 15~ Associated with the coupling member 22 is a ~ourth coupling member in the form of a threaded nut 27 which engages with the threaded sleeve portion 23 of the coupling ~ember 22 and is also rotatably coupled to a further coupling member 2~ having an internally threaded por~ion capable of engagement wlth the thread-ed sleeve portion 26 of the coupling me~ber 25.
Thus, in the coupling arrangement illustrated in Figure 3, the~coupting member 25 is coupled to the coupling member 20 by threaded engagement while the coupling member 27 is coupled to the coupling member 22 by threaded '- ~
engagement. Coupling between the members 25 and 27 is effected by threaded . -engagement between the coupling member 2g and the threaded s1eeve portion 26 of the coupling member 25 to draw the connector pins 12a and 12b axially toward one another to effect contact between the end faces thereo~ and proper axial alignment as determined by the alignment sleeve 15 This coup~ing arrangement provides for simplified assem~ly and disassembly of the connection between the connec~or p;ns, and not ~nly assures proper con~act between the ' ':
ends of the connector pins~ but also proper alignment between the optical fibers carried thereby.
It will be noted that the connector pin-couplina arrangem nt for each of the pair of ~ibers to be coupled is identical in ~hat the connector pins are identical and the coupling members 20 and 2~ are identical~ Thus, either connector may comprise the male or female portion and carry the alignment sleeve 1~. In the example illustrated in Figure 3~ the alignment sleeve 15 is mounted on connector pin lZa and a spacing member 40 is mounted on connector . i .
pin 12b, but the elements 15 and 40 could be reversed with no effect, thereby providing very simplified assembly and disassembly of the arrangement facilitating iber end cleaning in the ~ield.
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01 The details of the female connector in accordance ,7ith 02 the present invention is illustrated in Figure 4. After the 03 single fiber optic strand has been mounted in the connector pin 04 12a in the manner described in connection with Figure 1, an 05 insulating tubing 31, ~hich may be formed of Teflon*, is 06 provided over the remaining fiber of protection and is attached 07 to the connector pin 12a by means of a heat shrink tubing 32.
08 The optical fiber with the pin attached is then 09 assembled into the connector back shell 34 made of a rigid material, such as metal, and is properly positioned inside the 11 connector body using a tool that will ensure proper axial 12 positioning of the optical fiber lOa. A flexible adhesive 13 material 33, such as RT~ adhesive, is then disposed in the 14 region between the connector pin 12a and the metallic back shell 34 of the connector portion so as to maintain the connector pin ~16 in proper position while also providing a resilient base 17 permitting slight movement of the pin 12a with respect to the ~lB connector shell 34. In this way proper axial alignment between 19 the fibers is effected and maintained by the alignment sleeve 15 rather than the back shell 34. The fiber cable jacket 35 which 21 IS made of a material having high tensile strength and a low 22 modulus of elasticity, such as fiherglass, is then bonded to the 23 connector back shell 34 and a heat shrink tubing 36 is provided 24 over the connection serving not only to seal the connection but ~25 also provide a strain relief therefor. Disposed between the 26 alignment sleeve 15 and the female connector 20 is a bushing 19 ~27 made of flexible material, such as Teflon which also serves as 28 an adhesive stop.
29 The male connector member in accordance with the present invention, as seen in Figure 5, corresponds ~31 substantially identically to the female connector portion. In 32 fact, either connector portion may be provided as the male or 33 *Trade Mark 34 ~ 9 _ . ~ .
01 Eemale connector with the alignment sleeve 15 being mounted on 02 either one of the connector portions as indicated in conjunction 03 with Figure 3. In this regard, the spacing member 40 of 04 insulating material, such as Teflon, and having a metallic 05 sheath is provided on the male connector while the alignment : -~
. 17 ~18 ~ 19 ~23 ~25 ~26 32 - 9a -~6 sleeve 15 is provided on the female connector portion. In thi$ ~lay? the male and female connector portions may be constructed ;n an identical mannér with only the disposition of the spacer member 4Q and the alignment sieeye 1~ -determining which of the members is the male connector,and ~Ihich of the members is the female connector~
Loss tests have be.en m~de in connection with the connector and coupling arrange~ent illustra-ted in Figures 3 ~ 5? and performance results based on repeated connec~ions ~yherein the connector was unmated? rota~ed, and remated provided an average transmjss~on loss for all o~ the connections at 0.90 db, ~-~ith measured l~ss as low as ~.60 db. Thus, the present invention provides .
for proper a,l,ignment oF two optical fibers with extreme accuracy using con-.' 'nector and coupling means of simple construction providing for ease in mating and unmating a pair of optical fiber strandsr- The'use o~ the stainless steel connector pin construction enables polishing of the ~iber with ease and is a,lso, compati~ble ~ith ~iber ends that are cleaved prior to connector assembly,. The cable end of the connector assembly in accordance with the present inyenti.on ~s des,igned to perform three basic functions. First of all, 'the connector assembly provides for strain relie~ of the fiber as it emerges from J~he connector. It holds the ~iber/coupler assembly in the correc.t position .
for proper ma,ting~ and the resîlient adhesive provided between the connector pin and th.e connector back $hell proYides for flexing.of the mated connector ~' pins ts ens~re proper contact betwe.en the end sur~aces thereof and'sat.isfactory,' ~lignment w~thin th.e alignment sleeve.
While I h.aye. ~hown ~nd described an embod;ment in accordance with the present inyention~ it is understqod th.at the same is not limi;ted thereto but isl susceptible. of numerous changes and modi~ications as known to a per~on skilled !
in the art, and I therefQre do not wish tQ be limited to the detajls shown and descri,bed herein but intend to cover all such changes and modifications as are ~
obyious to one of ordinary skill in the art. ' ,' ~ ., ' . ..
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~ n addi,tion, the single optical fiber strand-to-strand connectors and couplers, of the prior art have been of generally large size so that use QF such couplers in a multi-strand cable of large size may be difficult, i~ nQt impossible. One such pr;or art connector and coupler arrangement i$ disclosed in U. $. Patent No. 3,914,880, issued to Dakss et al on October 28~ 1~75~ In th.e patented arrangement, the end of each optical fiber to be joi,ned is~ attached within a glass capillary and each glass .' capilla,,ry i,s inserted into a hollow hard ~etal plug ~hose ou~er surface is groun~ t,o a preci,sion diameter. The t~lo metal plugs are then placed in ,face.-to-face relatiQnsh.ip in a precision ground Y grooYe formed in a rigid b,lQck and are he.ld in pl'ace by respectiYe clamping arrangements in which ' holding scre~s conta,ct the respect;ve metal plu~s and hold them forcéfully th;n the grq~ye so as to maintain alignment between the.connectors by yirtue of th.e. precision Y grooye and the prec;sion ground, diameter of the-respec~iye me.~al plugs.
The s,tructural arran~ement of the connector and coupler combination disclQsed in the aboye-referenced Dakss et al patent clearly is of undesir~
ab'ly l~rge s,ize and o~ complicated construction rendering it generally un-des;rable for use in coupling optical fiber strands in a ~ultistrand cable.
In a~iti,on, the pro,per ali,gnmen~ between the respective connectors depends i,n t~.e p~tented coupl.~r arrargement solely upon the e~fectiveness o~ ~he cIa,mping ~rra;ngement associa~ed ~ith ~he suppor~ block in which is provided th.e. precision ~round V groove, the respect;ue connectors being held in po$ition on the Y groove by separate clamp;ng arrangements. Thus, a loosen-in~ o~ either clamping arran~emen~ dur;n~ use ~or any reason' can result in a Inisalign ent or uncoupIing of ~he Fibers~
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SUMMARY OF THE INVENTION
An object of the invention is to provide an improved fiber-to-fiber ; connector and coupler arrangement that can be mated and unmated under normal uses withou-t mechanical failure.
A further object o-F the present invent;on is to provide a connector and ' coupler arrangement of the type described in which coupl;ng and alignment of a pair of optical fibers can be ~aintained consistently w;th an insertion loss of less than ab'out 1.5 db without the need for matching or coupling oil.
¦ An addltional object of ~he inven~ion is to provide an improved sinyle fiber connector and coupling arrangement that is economical to fabricate, easy to assemble, and has the inherent ability to provide for easy change of the ~
ends o~ the fibers to maintain minimum loss in communication transmission. -,' ' Further, an object of the invention is to provide an improved single fiber connector that is compatible for use with fibers which are either - polished or cùt.
'A still additional object oF the invention is to proYide a single fiber ¦ 'connector in ~hich the fiber ends are in -Firm but resilient contact so that i low coup7iny losses are present without suhjecting the fiber ends to undue stress.
- In accordance with the present invention, an assem~ly for connectin~
the stripped ends of a pair of single optical fibers ;ncludes a pair df connector halves each comprisin9 a connector pin made o~ a rigid materiàl having a circular cross section and being formed with an ax;ally concentric precision circular aperture extending throughout the length of the pin, the aperture being shaped and sized so as to permit the s~ripped end of one of the !single optical fibérs' to be snu91y positioned and bonded within the aperture so that the fiber end and one pjn end are substantially coextensi~e. In order ¦to couple the respective ends of the pair Df optical fibers, the respective connector pins are placed in juxtaposed position with the ends thereof in con~act and a rigid adapter tube or alignment sleeve is disposed around the pair of connector pins so as to enclose the junct;on thereof and the port;ons thereof on either side, the aperture o~ the rigid tube be;ng shaped and sized ¦so as to hold the connector p;ns in close axial alignment.
h~
01 Acco~ding to the present inven-tion, a rigid shell 02 encloses a portion of each connector pin and extends beyond the 03 other end of the connector pin. A quantity of flexible adhesive 04 material is disposed in at least a portion of the region between 05 the connector pin and the rigid shell for permitting slight 06 movement of the pin with respect to the shell. Coupling means is 07 secured to -the rigid shell of both connector halves Eor drawing 08 the connector pins into pressure contact, the flexible adhesive 09 material providing a spring bias so that a resilient support of the connector pins in intimate contact with one another is 11 maintained. The adhesive material advantageously has an elastic 12 limit which releases the bond between the shell and connector pin 13 when excessive forces are generated, thereby minimizing damage to 14 the assembly. A flexible tube having a high tensile strength and low modulus of elasticity is tightly disposed over the back end 16 of the rigid shell and around the unstripped fiber portion.
17 More generally, the invention is a connector for a ~18 single strand optical fiber comprising a generally cylindrical ~19 connector pin made of a rigid material and being forrned with an axially concentric precision circular aperture extending 21 throughout the length of the pin, the aperture being shaped and 22 sized to permit a stripped end of a single optical fiber to ke 23 snuggly positioned within the aperture and bonded therein, and so ~24 positioned that the fiber end and one end of the pin are coplanar. A shell made of a rigid material encloses a portion of ~26 the connector pin and has a back end extending beyond the other ;27 end of the connector pin. A quantit~ of a flexible adhesive 28 material is disposed in at least a portion of the region between 29 the connector pin and the shell for permitting a slight movement of the connector pin with respect to the shell. The shell is 31 connected via further structure to an unstripped fiber portion.
32 _ 5 _ D
01 More particularly, the invention is a coupling asse~nbly 02 for connecting the stripped ends of a pair of single optical 03 fibers, comprising a pair of connectors, an alignment sleeve and 04 coupling structure for the connector pins. The pair of 05 connec-tors each is comprised of a generally cylindrical connector 06 pin made of a metallic material and formed with an axially 07 concen-tric precision circular aperture extending throughout the 08 length of the pin, the aperture being shaped and sized to permit 09 the stripped end of one of the single optical fibers to be snuggly positioned wi-thin the aperture, the fiber being 50 11 positioned that the fib~r end and one pin end are substantially 12 coextensive, an adhesive structure disposed between the material 13 of the connector pin defining the aperture and the surface of the 14 single fiber positioned in the aperture for securing the fiber to the connector pin, a first flexible tube surrounding an ~16 unstripped fiber portion of the single fiber and having one end ~17 spaced from the other end of the connector pin, and a heat 18 deformable tube disposed around a portion of the connector pin.
19 The unstripped ~iber portion is adjacent the connector pin and ~20 the flexible tube and is in a heat deformed condition so as to 21 form a flexible junction of the Elexible tube and the connector 22 pin with the fiher disposed therein. A metallic shell encloses a 23 portion of the connector pin and has a back end extending beyond 24 the other end o~ the connector pin. A second flexible tube having high tensile strength is tightly disposed over the back 26 end of the metallic shell and extends along the heat deformed 27 tube beyond the connector. A quantity of a flexible adhesive 28 material is disposed in the region between the connector pin and 29 the metallic shell for permitting slight movement of the pin with respect to the shell. The pair o~ connectors are joined such 31 - 5a -6~
01 that the ends of the connector pins and the single fibers a'out to 02 form a junction of the pair of single fibers. The alignment 03 sleeve is made of a rigid material disposed around -the pair of 04 connector pins such as to enclose the junction thereof and -the 05 portions thereof on either side. The aperture of the alignment 06 sleeve is shaped and sized so as to hold the connector pins in 07 close axial alignmen-t. The coupling structure is secured to the 08 metallic shell of both connectors for drawing -the connector pins 09 into pressure contact, the ~lexible adhesive material in each connector providing a spring bias so that a biased junction of 11 the pair of optical fibers results.
12 The invention, more particularly, is a single fiber 13 connector assembly comprising a single fiber whose end is 14 stripped of a protective jacket, a protective pin made of a metallic material and being formed with an axially aligned 16 circular aperture extending throughout the length thereof, the 17 stripped end of the single fiber being positioned in the aperture 18 such that ends of the fiber and the pin lie on a common plane, 19 the diameter of the aperture being slightly greater than the diameter of the fiber, and a quantity of first adhesive material 21 disposed between the inner walls of the connector pin and the 22 fiber to hold the fiber secure with respect to the pin. A Teflon 23 tube surrounds the remaining portion of the stripped fiber for 24 protection of the fiber. A structure is provided for attaching the tube to the end of the connector pin. The assembly also 26 includes a connector body having an axially aligned aper-ture, the 27 connector pin and attached fiber being located in spaced 28 relationship within the aperture. Structure including a 29 resilient adhesive material is disposed in the space between the pin and the connector body for holding the pin within the 31 connector body. A metallic alignment tube has an axial aperture 32 - 5b -s~
01 of uniform central circular diameter slightly larger than the 02 outer diameter of the connector pin. The end of the pin is 03 positioned within the alignment tube such that one end thereof is 04 flush with the end of the connector body. The tube has a length 05 such that the connector pin end does not protrude through the end 06 thereof and thereby is adapted to receive a similar pin of 07 another connector assembly to be adjoined thereto.
0~ These and other objects, features, and advantages of 09 the presen-t invention will become more apparent from the following detailed description, when taken in conjunction wit~ ~-11 the accompanying drawings.
~12 BRIEF DESCRIPTION OF THE DRAWIMGS
13 Figure 1 is a longitudinal sectional view of the fiber ~14 optical connector in accordance with the present invention;
Figure 2 is a schematic view partly in section of the ~16 general coupling arrangement by which alignment of a pair oS
17 connector pins is effected in accordance with the present 18 invention;
19 Figure 3 is a longitudinal sectional view of an assembled optical fiber connector and coupling arrangement, 21 showing the positions of both male and female connector portions, 22 according to the present invention, 23 Figure 4 is a longitudinal sectional view of the 24 complete female connector portion, shown partially in Figure 3;
;25 and ~26 Figure 5 is a partial sectional view of the male 27 connector portion which is utilized in connection with the female 28 connector portion illustrated in Figure 4.
31 - 5c -DETAILE~ DESCRIPTION OF THE REFERRED EMBODLMENT5 In referr;ng to the seYeral figures of the drawing, like reference numerals are used to refer to identical parts of the articles described.
The bas;c connector element in accordance with the present invention is illustra-ted in Figure 1 in the form of a connector pin 12 of generally cylindrical conFiguration made of r7g;d material7 such as stainless steel, and being formed with an axially concentric prec;sion circular aperture extending throu~hout the length of the pin. The aperture in one end of the pin is formed with an enlarged opening extending a short distance from the end. A -'s;ngle fiber optic strand 10 having a portion of its protective jacke-t str;ppedis then inserted into the enlarged aperture of the connector pin so that the ~-junction of the stripped and unstr;pped portion oF the fiber is pressed against'-the seat formed by the transit;on between the large and small d;ameter portions,of the connector pin aperture. In this regard, the fiber 10 is str;pped of its protective jacket along the len9th of the strand for a distQnce which will Ipermit the bare fiber 11 to extend through the entire length of the aperture ~ -in the connector pin 12 and protrude slightly from the opposite end 1~' thereo-FSuitable adhesive is disposed between the material oF the connector pin 1~ ¦ -defining the aperture and the surface of the single fiber positioned in the aperture for securing the fiber to the connector pin- The end 12' of the -¦
connector pin from which the fiber protrudes is then precision ground thereby providing a planar surface including both the end of the connector pin and t:he ¦
end of the optical ~iber mounted therein.
In another method o~ alignin9 the end of the fiber with the end of the connector pin, a~portion of the protective jacket is stripped and the fiber is cleaned. The cut end of the fiber is aligned with the end a~ the connector Pin~ and the junction of the str;pped and unstripped fiber is merely located within the larger diameter opening of the connector pin, as opposed to l~eing press against the seat . ' ., ' I
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The type of adhesive used to bond the ~iber to the connector pin ' ' depends upon the type of fiber being used. ~here the single fiber is formed 1.
of a glass central core material and a glass cladding material, the adhesive should have an index of refrac-tion greater than that of the material of tie cladding so that optical power in the cladding dissipates as it passes through the connector. One suitable adhesive for this purpose is epoxy. Where the single fiber is formed of a glass central core material and a plastic cladding-¦material, the adhesive material should have an ~ndex o~ refraction less than that of the glass core material. A preferred'adhesive for this purpose is.a l':
silicon-base~ RTV adhesive material. . ' - .
Proper alignment between a pair of connector pins in accordance ~ith the present invention is accomplished by use of an alignment sleeve 15 which is s;zed so as to hold a pair of connector pins in close axial alignment, as illustrated in Fi~ure 2. In this regard, a connector pin 12a into which an optical fiber 10a has been mounted in the manner described in connection with .
Figure 1 and having a protective jacke~ 13a is inserted into one end of the ~.
ali4nment sleeve 15; wh;le, a:second connector pin 12b having an aptical ~ er ,10b mounted therein and including a protec.tive jacket 13b is inserted into 'I-opposite end of the alignment sleeve 15. Proper dimensioning of the aperture in the alignment sleeve 15 provides a simple means for effectin~ axial align- !ment between the respective connector plns, and there~ore,'proper alignment between the optical ~ibers mounted in the connector p;ns. ¦ -A coupling arrangement for the optical ~iber connectors in accordance- ¦ ' with the present invention is.illustrated in Fi~ure 3. As seen in the ~igure~
a first coupling member.20 having a threaded sleeve portion 21 is mounted on one end o~ a first connector pin 12a with the free end of the connector pin extending into one end of an alignment sleeve 15 carried therèby. A second coupling member 22 havin~ a threaded sleeve portion 23 is mounted on one end of a second connecting pin 12b so that the free end of the connecting pin extends into the other end of the alignment sleeve 15 in abutting relationship ith the connecting pin 12a. The connecting pins 12a and 12b are ~ormed in the manner described in connection with Figure I and alignment between these '. " : .
connecting pins is effected by means of the.al1gnrnent sleeve 15 as described in connection with Figure 2. - ~, Associated with the coupling member 20 is a third coupling member in the form of a nut 2~ having an internally threaded portion w~ich engages the threaded sleeve member 21 of the coupling member 20 and has an externally threaded sleeve portion 26 extending over the alignment sleeve 15~ Associated with the coupling member 22 is a ~ourth coupling member in the form of a threaded nut 27 which engages with the threaded sleeve portion 23 of the coupling ~ember 22 and is also rotatably coupled to a further coupling member 2~ having an internally threaded por~ion capable of engagement wlth the thread-ed sleeve portion 26 of the coupling me~ber 25.
Thus, in the coupling arrangement illustrated in Figure 3, the~coupting member 25 is coupled to the coupling member 20 by threaded engagement while the coupling member 27 is coupled to the coupling member 22 by threaded '- ~
engagement. Coupling between the members 25 and 27 is effected by threaded . -engagement between the coupling member 2g and the threaded s1eeve portion 26 of the coupling member 25 to draw the connector pins 12a and 12b axially toward one another to effect contact between the end faces thereo~ and proper axial alignment as determined by the alignment sleeve 15 This coup~ing arrangement provides for simplified assem~ly and disassembly of the connection between the connec~or p;ns, and not ~nly assures proper con~act between the ' ':
ends of the connector pins~ but also proper alignment between the optical fibers carried thereby.
It will be noted that the connector pin-couplina arrangem nt for each of the pair of ~ibers to be coupled is identical in ~hat the connector pins are identical and the coupling members 20 and 2~ are identical~ Thus, either connector may comprise the male or female portion and carry the alignment sleeve 1~. In the example illustrated in Figure 3~ the alignment sleeve 15 is mounted on connector pin lZa and a spacing member 40 is mounted on connector . i .
pin 12b, but the elements 15 and 40 could be reversed with no effect, thereby providing very simplified assembly and disassembly of the arrangement facilitating iber end cleaning in the ~ield.
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01 The details of the female connector in accordance ,7ith 02 the present invention is illustrated in Figure 4. After the 03 single fiber optic strand has been mounted in the connector pin 04 12a in the manner described in connection with Figure 1, an 05 insulating tubing 31, ~hich may be formed of Teflon*, is 06 provided over the remaining fiber of protection and is attached 07 to the connector pin 12a by means of a heat shrink tubing 32.
08 The optical fiber with the pin attached is then 09 assembled into the connector back shell 34 made of a rigid material, such as metal, and is properly positioned inside the 11 connector body using a tool that will ensure proper axial 12 positioning of the optical fiber lOa. A flexible adhesive 13 material 33, such as RT~ adhesive, is then disposed in the 14 region between the connector pin 12a and the metallic back shell 34 of the connector portion so as to maintain the connector pin ~16 in proper position while also providing a resilient base 17 permitting slight movement of the pin 12a with respect to the ~lB connector shell 34. In this way proper axial alignment between 19 the fibers is effected and maintained by the alignment sleeve 15 rather than the back shell 34. The fiber cable jacket 35 which 21 IS made of a material having high tensile strength and a low 22 modulus of elasticity, such as fiherglass, is then bonded to the 23 connector back shell 34 and a heat shrink tubing 36 is provided 24 over the connection serving not only to seal the connection but ~25 also provide a strain relief therefor. Disposed between the 26 alignment sleeve 15 and the female connector 20 is a bushing 19 ~27 made of flexible material, such as Teflon which also serves as 28 an adhesive stop.
29 The male connector member in accordance with the present invention, as seen in Figure 5, corresponds ~31 substantially identically to the female connector portion. In 32 fact, either connector portion may be provided as the male or 33 *Trade Mark 34 ~ 9 _ . ~ .
01 Eemale connector with the alignment sleeve 15 being mounted on 02 either one of the connector portions as indicated in conjunction 03 with Figure 3. In this regard, the spacing member 40 of 04 insulating material, such as Teflon, and having a metallic 05 sheath is provided on the male connector while the alignment : -~
. 17 ~18 ~ 19 ~23 ~25 ~26 32 - 9a -~6 sleeve 15 is provided on the female connector portion. In thi$ ~lay? the male and female connector portions may be constructed ;n an identical mannér with only the disposition of the spacer member 4Q and the alignment sieeye 1~ -determining which of the members is the male connector,and ~Ihich of the members is the female connector~
Loss tests have be.en m~de in connection with the connector and coupling arrange~ent illustra-ted in Figures 3 ~ 5? and performance results based on repeated connec~ions ~yherein the connector was unmated? rota~ed, and remated provided an average transmjss~on loss for all o~ the connections at 0.90 db, ~-~ith measured l~ss as low as ~.60 db. Thus, the present invention provides .
for proper a,l,ignment oF two optical fibers with extreme accuracy using con-.' 'nector and coupling means of simple construction providing for ease in mating and unmating a pair of optical fiber strandsr- The'use o~ the stainless steel connector pin construction enables polishing of the ~iber with ease and is a,lso, compati~ble ~ith ~iber ends that are cleaved prior to connector assembly,. The cable end of the connector assembly in accordance with the present inyenti.on ~s des,igned to perform three basic functions. First of all, 'the connector assembly provides for strain relie~ of the fiber as it emerges from J~he connector. It holds the ~iber/coupler assembly in the correc.t position .
for proper ma,ting~ and the resîlient adhesive provided between the connector pin and th.e connector back $hell proYides for flexing.of the mated connector ~' pins ts ens~re proper contact betwe.en the end sur~aces thereof and'sat.isfactory,' ~lignment w~thin th.e alignment sleeve.
While I h.aye. ~hown ~nd described an embod;ment in accordance with the present inyention~ it is understqod th.at the same is not limi;ted thereto but isl susceptible. of numerous changes and modi~ications as known to a per~on skilled !
in the art, and I therefQre do not wish tQ be limited to the detajls shown and descri,bed herein but intend to cover all such changes and modifications as are ~
obyious to one of ordinary skill in the art. ' ,' ~ ., ' . ..
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Claims (27)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A connector for a single strand optical fiber comprising (a) a generally cylindrical connector pin made of a rigid material and being formed with an axially concentric precision circular aperture extending throughout the length of the pin, the aperture being shaped and sized to permit a stripped end of a single optical fiber to be snugly positioned within the aperture and bonded therein, and so positioned that the fiber end and one end of the said pin are co-planar;
(b) a shell made of a rigid material enclosing a portion of the connector pin and having a back end extending beyond the other end of the connector pin;
(c) a quantity of a flexible adhesive material disposed in at least a portion of the region between the connector pin and the shell for permitting slight movement of the connector pin with respect to the shell; and (d) means for connecting the shell to an unstripped fiber portion.
(b) a shell made of a rigid material enclosing a portion of the connector pin and having a back end extending beyond the other end of the connector pin;
(c) a quantity of a flexible adhesive material disposed in at least a portion of the region between the connector pin and the shell for permitting slight movement of the connector pin with respect to the shell; and (d) means for connecting the shell to an unstripped fiber portion.
2. A connector according to claim 1 wherein the connecting means includes a flexible tube having a high tensile strength and low modulus of elasticity disposed around the unstripped fiber portion and being bonded to the back end of the shell.
3. A connector according to claim 2 wherein the shell has an outer threaded portion for engagement with a coupling means for coupling the connector to another connector.
4. A connector according to claim 2, further including an additional flexible tube within the flexible tube of high tensile strength and low modulus of elasticity and surrounding the unstripped fiber portion in spaced relation thereto and to the connector pin, and a heat deformable tube disposed around a portion of the connector pin and the additional flexible tube and being in heat deformed condition so as to form a flexible junction of the additional flexible tube and the connector pin with the optical fiber diposed therein.
5. A connector according to claim 1 wherein the connector pin is made of a metallic material.
6. A connector according to claim 5 wherein the connector pin is made of stainless steel.
7. A connector according to claim 5 wherein the connector pin is formed such that the aperture in one end of the pin has an enlarged opening extending a short distance so as to form an enclosure for the junction of the stripped and the unstripped portions of the optical fiber.
8. A connector according to claim 7 wherein the enlarged opening in the connector pin forms a seat for the junction of the stripped and unstripped portions of the optical fiber so that the junction is in contact with the end of the enlarged opening.
9. A coupling assembly for connecting the unstripped ends of a pair of single optical fibers comprising:
(a) a pair of connectors each comprising (1) a generally cylindrical connector pin made of a metallic material and being formed with an axially concentric precision circular aperture extending throughout the length of the pin, the aperture being shaped and sized to permit the stripped end of one of the single optical fibers to be snugly positioned within the aperture, the fiber being so positioned that the fiber end and one pin end are substantially coextensive;
(2) adhesive means disposed between the material of the connector pin defining the aperture and the surface of the single fiber positioned in the aperture for securing the fiber to the connector pin;
(3) a first flexible tube surrounding an unstripped fiber portion of said single fiber and having one end spaced from the other end of the connector pin, (4) a heat deformable tube disposed around a portion of the connector pin, the unstripped fiber portion adjacent the connector pin and the flexible tube and being in a heat deformed condition so as to form a flexible junction of the flexible tube and the connector pin with the fiber disposed therein;
(5) a metallic shell enclosing a portion of the connector pin and having a back end extending beyond the other end of the connector pin;
(6) a second flexible tube having high tensile strength tightly disposed over the back end of the metallic shell and extending along the heat deformed tube beyond the connector;
~ 7) a quantity of a flexible adhesive material disposed in the region between the connector pin and the metallic shell for permitting slight movement of the pin with respect to the shell;
(b) the pair of connectors being joined such that the ends of the connector pins and the single fibers abut to form a junction of the pair of single fibers;
(c) an alignment sleeve made of a rigid material disposed around the pair of connector pins such as to enclose the junction thereof and the portions thereof on either side, the aperture of the alignment sleeve being shaped and sized so as to hold the connector pins in close axial alignment; and (d) coupling means secured to the metallic shell of both connectors for drawing the connector pins into pressure contact, said flexible adhesive material in each connector providing a spring bias so that a biased junction of the pair of optical fibers results.
(a) a pair of connectors each comprising (1) a generally cylindrical connector pin made of a metallic material and being formed with an axially concentric precision circular aperture extending throughout the length of the pin, the aperture being shaped and sized to permit the stripped end of one of the single optical fibers to be snugly positioned within the aperture, the fiber being so positioned that the fiber end and one pin end are substantially coextensive;
(2) adhesive means disposed between the material of the connector pin defining the aperture and the surface of the single fiber positioned in the aperture for securing the fiber to the connector pin;
(3) a first flexible tube surrounding an unstripped fiber portion of said single fiber and having one end spaced from the other end of the connector pin, (4) a heat deformable tube disposed around a portion of the connector pin, the unstripped fiber portion adjacent the connector pin and the flexible tube and being in a heat deformed condition so as to form a flexible junction of the flexible tube and the connector pin with the fiber disposed therein;
(5) a metallic shell enclosing a portion of the connector pin and having a back end extending beyond the other end of the connector pin;
(6) a second flexible tube having high tensile strength tightly disposed over the back end of the metallic shell and extending along the heat deformed tube beyond the connector;
~ 7) a quantity of a flexible adhesive material disposed in the region between the connector pin and the metallic shell for permitting slight movement of the pin with respect to the shell;
(b) the pair of connectors being joined such that the ends of the connector pins and the single fibers abut to form a junction of the pair of single fibers;
(c) an alignment sleeve made of a rigid material disposed around the pair of connector pins such as to enclose the junction thereof and the portions thereof on either side, the aperture of the alignment sleeve being shaped and sized so as to hold the connector pins in close axial alignment; and (d) coupling means secured to the metallic shell of both connectors for drawing the connector pins into pressure contact, said flexible adhesive material in each connector providing a spring bias so that a biased junction of the pair of optical fibers results.
10. The assembly according to claim 9 wherein the single fiber is formed of a glass central core material and a glass cladding material and wherein said adhesive means is an epoxy material having an index of refraction greater than that of the material of the cladding so that optical power in the cladding dissipates as it passes through the connector.
11. The assembly according to claim 9 wherein the single fiber is formed of a glass central core material and a plastic cladding material and wherein said adhesive means is an adhesive material having an index of refraction less than that of the glass central core material.
12. The assembly according to claim 9 wherein the connector pins are made of stainless steel.
13. The assembly according to claim 9 wherein said alignment sleeve is made of brass.
14. The assembly according to claim 9 wherein said alignment sleeve is made of a plastic material.
15. The assembly according to claim 12 wherein each connector pin is formed such that the aperture in one end of the pin has an enlarged opening extending a short distance so as to form an enclosure for the junction of the stripped and unstripped portions of the single optical fiber.
16. The assembly according to claim 9 further including a bushing made of a flexible material disposed between each end of said alignment sleeve and the respective end of the metallic sleeve.
17. The assembly according to claim 16 wherein the coupling means includes first and second coupling members threaded to the shell of a respective connector and having mating threaded portions for engagement with one another.
18. A single fiber connector assembly comprising (a) a single fiber whose end is stripped of a protective jacket;
(b) a connector pin made of a metallic material and being formed with an axially aligned circular aperture extending throughout the length thereof, the stripped end of the single fiber being positioned in the aperture such that ends of the fiber and the pin lie on a common plane, the diameter of the aperture being slightly greater than the diameter of the fiber;
(c) a quantity of first adhesive material being disposed between the inner walls of the connector pin and the fiber to hold the fiber secure with respect to the pin;
(d) a Teflon tube surrounding the remaining portion of the stripped fiber for protection of the fiber;
(e) means for attaching the tube to the end of the connector pin;
(f) a connector body having an axially aligned aperture, the connector pin and attached fiber being located in spaced relationship within said aperture;
(g) means comprising a resilient adhesive material disposed in the space between said pin and said connector body for holding the pin within the connector body, and (h) a metallic alignment tube having an axial aperture of uniform central circular diameter slightly larger than the outer diameter of the connector pin, the end of the pin being positioned in the alignment tube such that one end thereof is flush with the end of the connector body, the tube having a length such that the connector pin end does not protrude through the end thereof and thereby is adapted to receive a similar pin of another connector assembly to be adjoined thereto.
(b) a connector pin made of a metallic material and being formed with an axially aligned circular aperture extending throughout the length thereof, the stripped end of the single fiber being positioned in the aperture such that ends of the fiber and the pin lie on a common plane, the diameter of the aperture being slightly greater than the diameter of the fiber;
(c) a quantity of first adhesive material being disposed between the inner walls of the connector pin and the fiber to hold the fiber secure with respect to the pin;
(d) a Teflon tube surrounding the remaining portion of the stripped fiber for protection of the fiber;
(e) means for attaching the tube to the end of the connector pin;
(f) a connector body having an axially aligned aperture, the connector pin and attached fiber being located in spaced relationship within said aperture;
(g) means comprising a resilient adhesive material disposed in the space between said pin and said connector body for holding the pin within the connector body, and (h) a metallic alignment tube having an axial aperture of uniform central circular diameter slightly larger than the outer diameter of the connector pin, the end of the pin being positioned in the alignment tube such that one end thereof is flush with the end of the connector body, the tube having a length such that the connector pin end does not protrude through the end thereof and thereby is adapted to receive a similar pin of another connector assembly to be adjoined thereto.
19. The connector assembly according to claim 18 wherein the first adhesive material is epoxy.
20. The connector assembly according to claim 18 wherein the first adhesive material is silicon based RTV.
21. The connector assembly according to claim 18 wherein the aperture in the connector pin is formed with an enlarged region at one end thereof.
22. The connector assembly according to claim 18 further including a resilient bushing disposed between said connector body and said alignment tube to act as an adhesive stop.
23. The connector assembly according to claim 18 wherein said resilient adhesive material is an RTV adhesive material.
24. The connector assembly according to claim 18 wherein the connector pin is made of stainless steel tubing.
25. The connector assembly according to claim 18 wherein the adhesive means includes means for providing loading on the mated pin.
26. A coupling assembly according to claim 23, wherein said alignment tube is removably disposed around said pair of connector pins so as to permit simplified access to said connector pins and the optical fibers positioned therein.
27. A coupling assembly according to claim 14, wherein said alignment sleeve is removably disposed around said pair of connector pins so as the permit simplified access to said connector pins and the optical fibers positioned therein.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000378179A CA1143976A (en) | 1977-04-19 | 1981-05-22 | Fiber optic connector for single fiber |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US788,768 | 1977-04-19 | ||
| US05/788,768 US4205897A (en) | 1977-04-19 | 1977-04-19 | Fiber optic connector for single fiber |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1106666A true CA1106666A (en) | 1981-08-11 |
Family
ID=25145497
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA294,055A Expired CA1106666A (en) | 1977-04-19 | 1977-12-29 | Fiber optic connector for single fiber |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US4205897A (en) |
| CA (1) | CA1106666A (en) |
Families Citing this family (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5674210A (en) * | 1979-11-21 | 1981-06-19 | Nec Corp | Optical fiber connector |
| US4406514A (en) * | 1980-03-26 | 1983-09-27 | Harris Corporation | Single fiber connector for pluggable card or module optical interconnections |
| US4383736A (en) * | 1980-11-24 | 1983-05-17 | The United States Of America As Represented By The Secretary Of The Navy | Pressure formed fiber optic connector |
| US4413880A (en) * | 1981-01-02 | 1983-11-08 | Bowmar/Ali, Inc. | Adaptable connector for a fiber optic testing device |
| DE3381297D1 (en) * | 1982-06-05 | 1990-04-12 | Amp Inc | PLUG TO CONNECT TO AN OPTICAL FIBER. |
| GB8310131D0 (en) * | 1983-04-14 | 1983-05-18 | British Telecomm | Sealing assembly |
| US4850670A (en) * | 1983-08-29 | 1989-07-25 | American Telephone And Telegraph Company, At&T Bell Laboratories | Optical fiber connector comprising drawn glass tubes |
| US4934785A (en) * | 1983-08-29 | 1990-06-19 | American Telephone And Telegraph Company | Optical fiber connector |
| US4896938A (en) * | 1983-08-29 | 1990-01-30 | American Telephone And Telegraph Company, At&T Bell Laboratories | Optical fiber connector comprising glass tubes |
| US4838640A (en) * | 1983-12-19 | 1989-06-13 | Gte Products Corporation | Fiber optic in-line splice case assembly |
| US4913512A (en) * | 1983-12-19 | 1990-04-03 | Gte Products Corporation | Fiber optic in-line splice case assembly |
| US4636033A (en) * | 1984-05-14 | 1987-01-13 | At&T Bell Laboratories | Optical fiber splice and methods of making |
| WO1991003755A1 (en) * | 1989-08-29 | 1991-03-21 | Fibotech, Inc. | High precision fiberoptic alignment spring receptacle and fiberoptic probe |
| USRE36231E (en) * | 1989-10-31 | 1999-06-22 | Fibotech, Inc. | Fiberoptic connector assembly and method and device for the manufacture thereof |
| US5216735A (en) * | 1989-10-31 | 1993-06-01 | Fibotech, Inc. | Metal core fiberoptic connector plug for single fiber and multiple fiber coupling |
| DE59302988D1 (en) * | 1992-05-20 | 1996-07-25 | Diamond Sa | Connector for an optical fiber |
| US5502784A (en) * | 1994-07-01 | 1996-03-26 | Valquest Medical, Inc. | Heat insulating connector for plastic optical fibers |
| US5822483A (en) * | 1994-08-12 | 1998-10-13 | Fibotech, Inc. | Double impact mounted ferrule for fiberoptic connector |
| US5563971A (en) * | 1995-04-28 | 1996-10-08 | The Whitaker Corporation | Floating bottleneck for multiple position fiber optic receptacle |
| US5608828A (en) * | 1995-09-12 | 1997-03-04 | Itt Corporation | Fiber optic connector apparatus |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3455625A (en) * | 1966-06-23 | 1969-07-15 | Bausch & Lomb | Optical fiber bundle coupling system |
| US4009931A (en) * | 1974-03-20 | 1977-03-01 | The Deutsch Company Electronic Components Division | Optical waveguide connector |
| FR2273289A1 (en) * | 1974-05-30 | 1975-12-26 | Fort Francois | Connector for optical fibres - has bored components with conical male and female coupling ends |
| JPS50156448A (en) * | 1974-06-05 | 1975-12-17 | ||
| GB1458897A (en) * | 1974-07-09 | 1976-12-15 | Cannon Electric Great Britain | Connectors |
| GB1480444A (en) * | 1975-05-06 | 1977-07-20 | Standard Telephones Cables Ltd | Termination of optical fibres |
| US4008948A (en) * | 1975-06-30 | 1977-02-22 | Northern Telecom Limited | Optical fibre connectors |
| US4061577A (en) * | 1976-08-18 | 1977-12-06 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Fiber optic multiplex optical transmission system |
-
1977
- 1977-04-19 US US05/788,768 patent/US4205897A/en not_active Expired - Lifetime
- 1977-12-29 CA CA294,055A patent/CA1106666A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US4205897A (en) | 1980-06-03 |
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| Date | Code | Title | Description |
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| MKEX | Expiry |